Fire Spells Glitch

For some reason fire spells do not regonize power pips. For example, if I wanted to use a Fire Bird spell, which requires four pips, and have two power pips (one power pip is equal to two regular pips), the game won't allow me to use the spell. Also, if I were to have two power pips and two regular pips (that's six pips in total) and use the Fire Bird spell, it would consume all six pips when it only needed four. I believe this is the case with all fire spells and would appreciate it if this glitch would be corrected. Thank You for listening (reading)!